Figure 3. Tumor histology and cell proliferation. (A) Untreated control, (B) PIO alone, (C) CDDP alone, (D) CDDP + PIO. Scale bars: 100 μm. Ki-67 immunohistochemical staining (E-H). (E) Control, (F) PIO only, (G) CDDP only, (H) CDDP + PIO. (I) Percentage of Ki-67 positive cells in control and each treatment group. Scale bars: 100μm. *p<0.05. Error bars: ±SEM.